JP3476409B2 - Plasma CVD equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma CVD apparatus, and particularly to a silicon nitride film (SiN film).
And a fluorine-containing silicon oxide film (SiOF film) continuously in the same chamber.

[0002]

2. Description of the Related Art With the miniaturization of semiconductor elements, fine multilayer wiring of semiconductor devices has become essential. In order to prevent the operation speed delay of the semiconductor device, it is desired to use Cu wiring for the wiring, and it is necessary to use a low dielectric constant film for the interlayer insulating film.

It is considered that the low dielectric constant film can be commercialized relatively early by using the SiOF film which can be easily integrated in the same manufacturing process as the conventionally used silicon oxide film (SiO ₂ film). ing.

Further, in general, the formation of the interlayer insulating film on the Cu wiring is performed after the SiN film is formed in order to prevent the Cu wiring from being oxidized.
The method of forming the iO ₂ film is used, and in these steps, it is desirable to continuously form the SiN film and the SiO ₂ film in the same chamber in order to reduce the cost. When changing from a SiO ₂ film to a SiOF film to lower the dielectric constant,
Similarly, continuous film formation in the same chamber is desired.

Next, referring to FIG. 5, the SiN film and the S
A conventional example in which an iOF film is formed in the same chamber will be described.

Referring to the sectional view of FIG. 5, this example shows a parallel plate type plasma CVD apparatus. The configuration of the apparatus is as follows: N ₂ O gas pipe 1 in which a final valve 12 is installed in a chamber 11, SiF ₄ gas pipe 2, NH
_The final valve 23 is installed after the ₃ gas pipe 3 and the SiH ₄ gas pipe 4 join the same line,
The pipe is connected to the chamber 11. A shower head / upper electrode 7 and a high-frequency power source 5 are provided above the chamber 11, and a heater / lower electrode 9 to which a low-frequency power source 6 is connected is provided at the lower portion of the chamber.
Is installed. Then, the exhaust unit 10 is provided on the side wall of the chamber.
Is provided.

Next, the steps of film formation will be described. First, as the first step, the NH ₃ gas valve 15, the SiH ₄ gas valve 16 and the final valve 23 are opened to
₃ gas and SiH ₄ gas are introduced into the chamber 11,
A SiN film was formed. The substrate temperature was controlled at 400 ° C. and the chamber pressure was controlled at 4-5 Torr. The power of the high frequency power supply 5 and the power of the low frequency power supply 6 are each about 500
By applying W and 500 W, a SiN film having a film thickness of about 100 nm was formed on the wafer 8 in this step.

Next, as a second step, after forming the SiN film, the high frequency power source 5 and the low frequency power source 6 are turned off,
By closing the NH ₃ gas valve 15 and the SiH ₄ gas valve 16, the introduction of the SiH ₄ gas and the NH ₃ gas is stopped, and the SiF ₄ gas valve 13A, the NH ₃ gas valve 15, and the SiH ₄ gas valve 16 remain in the pipe between the chambers 11. Exhaust gas.

Next, the final valve 12, the SiF ₄ gas valve 13A, and the SiH ₄ which are N ₂ O gas valves.
By opening the gas valve 16 and the final valve 23, N ₂ O gas, SiF ₄ gas and SiH ₄ gas were introduced into the chamber 11 to try to form a SiOF film.
Substrate temperature is 400 ° C, chamber pressure is 4-5 Torr
Controlled.

By applying the powers of the high frequency power source 5 and the low frequency power source 6 to about 500 W and 500 W, respectively,
At this stage, the SiOF film was to be formed on the wafer 8 but only the reaction product particles were attached. At this step, the pipe was clogged and the gas stopped flowing. Final valve 2
When the pipes near 3 were removed and analyzed, [(NH
₄ ) ₂ SiF ₆ ], the reaction product was confirmed by analysis. This confirmed that SiF ₄ and NH ₃ react at room temperature and under vacuum.

Next, since SiF ₄ and NH ₃ react at room temperature, continuous film formation in the same chamber was abandoned, and Si
A method of forming the N film and the SiOF film in different chambers will be described with reference to the sectional views of FIGS. 6 and 7.

FIG. 6 shows a chamber 11 for depositing a SiN film, which is opened by opening a final valve 14.
NH ₃ gas and SiH ₄ gas are introduced into the chamber 11 to form a SiN film. The substrate temperature was controlled at 400 ° C. and the chamber pressure was controlled at 4-5 Torr.

Each gas is introduced into the chamber 11 from the NH ₃ gas pipe 3 and the SiH ₄ gas pipe 4. The power of the high frequency power source 5 and the power of the low frequency power source 6 are each about 500.
By applying W and 500 W, a SiN film having a film thickness of about 100 nm was formed on the wafer 8 at this stage.

After further vacuuming, the atmosphere is returned to the atmosphere with N ₂ gas, the wafer 8 is transferred to another chamber, and then S shown in FIG.
The film was transferred to the iOF film forming chamber 11.

FIG. 7 shows a chamber 11 for forming a SiOF film. By opening the final valves 12 and 14B, N ₂ O gas and SiF ₄ gas are supplied to the chamber 11.
And a SiOF film was formed. Substrate temperature 400 ℃,
The chamber pressure was controlled to 4-5 Torr. The power of the high-frequency power supply 5 and the low-frequency power supply 6 is about 500 each.
By applying W and 500 W, the SiOF film is formed on the wafer 8 at this stage.

In this method, two chambers are used, and the throughput becomes slow when the time for carrying them is taken into consideration, and the cost of the apparatus increases due to the use of the two chambers. was there.

[0017]

First, the conventional gas pipe shown in FIG. 5 has a device form in which NH ₃ gas and SiF ₄ gas are introduced into the chamber through the same gas pipe.
Only a common final valve is installed, and NH ₃
Since gas exhaust is incomplete and NH ₃ gas and SiF ₄ gas are mixed in the gas pipe in front of the chamber, they react at room temperature and the reaction product of NH ₃ and SiF ₄ [(NH
₄ ) ₂ SiF ₆ ] was generated, and there was a problem in that the number of particles on the wafer increased due to the reaction in the pipe, that is, the generation of the pipe.

Further, in order to avoid the reaction, in the method of forming the SiN film and the SiOF film in the different chambers as described with reference to FIGS. 6 and 7, the throughput becomes slow and the apparatus cost becomes high. was there.

An object of the present invention is to prevent clogging of piping,
An object of the present invention is to provide a plasma CVD apparatus capable of forming a SiN film and a SiOF film in the same chamber.

[0020]

Means for Solving the Problems Plasma C of the first invention
The VD apparatus is a plasma CVD apparatus for forming a silicon nitride film and a fluorine-containing silicon oxide film in the same chamber, and NH _{3 is used} as a part of a raw material gas for the silicon nitride film.
Those wherein the NH ₃ gas pipe for introducing a gas, that is connected to the fluorine-containing silicon oxide film SiF ₄ gas separately showerhead-upper electrode piping for introducing SiF ₄ gas as a part of the raw material gas is there.

The plasma CVD apparatus of the second invention is a plasma CVD apparatus for forming a silicon nitride film and a fluorine-containing silicon oxide film in the same chamber. NH ₃ gas is introduced as a part of the raw material gas for the silicon nitride film.
₃ has a gas pipe, each separate valve in front of SiF ₄ gas pipe merges to introduce SiF ₄ gas as part of the raw material gas of the fluorine-containing silicon oxide film, SiF ₄
The valve installed in the gas pipe and the valve installed in the NH ₃ gas pipe are interlocked with each other, and when one is open, the other is closed.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a parallel plate type plasma CV for explaining the first embodiment of the present invention.
It is sectional drawing of D device.

Referring to FIG. 1, in the parallel plate type plasma CVD apparatus of the present invention, an N ₂ O gas pipe 1 provided with a final valve 12 is connected to a shower head / upper electrode outer peripheral portion 7A. Further, the NH ₃ gas pipe 3 and the SiH ₄ gas pipe 4 are connected to the same pipe, and then connected to the shower head / upper electrode outer peripheral portion 7A via the final valve 14. Further, the SiF ₄ gas pipe 2 in which the final valve 13 is installed is connected to the shower head / upper electrode central portion 7B. In the upper part of the chamber 11, the outer peripheral part of the shower head and upper electrode and the central part 7A
7B and a high frequency power source 5, a heater / lower electrode 9 for placing the wafer 8 on the lower portion of the chamber, a low frequency power source 6 and an exhaust portion 10 on the side wall of the chamber.

FIG. 2 is a sectional view of a parallel plate type plasma CVD apparatus showing a second embodiment of the present invention, in which the N ₂ O gas pipe 1 provided with a final valve 12 serves as a shower head / upper electrode 7. It is connected. Also valve 15
After the NH ₃ gas pipe 3 in which is installed and the SiH ₄ gas pipe 4 in which the valve 16 is installed are connected to the same line,
SiF having valve 13 through final valve 14
₄ It joins the gas pipe 2 and is connected to the shower head / upper electrode 7. Shower head / upper electrode 7 and high frequency power source 5 are provided above the chamber 11, and wafer 8 is provided below the chamber.
A lower electrode 9 also serving as a heater for mounting a heater, a low-frequency power source 6, and an exhaust unit 10 are provided on the side wall of the chamber.

FIG. 3 is a sectional view of a high-density plasma CVD apparatus showing a third embodiment of the present invention. The N ₂ O gas pipe 1 in which the final valve 12 is installed and the SiF ₄ gas pipe 2 in which the final bubble 13 is installed are connected to the chamber 11A. Also, NH ₃ gas pipe 3 and Si
After the H ₄ gas pipe 4 is connected to the same line, it is connected to the chamber 11A via the final valve 14. Each gas is introduced into the chamber through the gas slurries 1A, 2A and 3A. The coil 17 and the high frequency power source 5A are provided on the dome portion above the chamber 11A, the heater / lower electrode 9 and the high frequency power source 5B for mounting the wafer 8 on the lower portion of the chamber, and the exhaust portion 10A are provided on the side wall of the chamber.

FIG. 4 shows a parallel plate type plasma CVD apparatus according to a fourth embodiment of the present invention, in which an N ₂ O gas pipe 1 provided with a final bubble 12 is connected to a shower head / upper electrode 7. There is. Also NH ₃ gas valve 1
After the NH ₃ gas pipe 3 in which No. ₅ is installed and the SiH ₄ pipe 4 in which the SiF ₄ gas valve 16 is installed are connected to the same line, the NH ₃ · SiH ₄ valve 14A is installed. Furthermore its pipe and N ₂ gas valve 19 is installed N ₂ gas pipe 18 and SiF ₄ SiF ₄ gas pipe 2 gas valve 13A is installed, are divided into two hands coupled to the same line, one exhaust valve 22 Is connected to the gas exhaust unit 21 via the, and the other is connected to the shower head / upper electrode 7 via the final valve 20. Shower head / upper electrode 7 and high frequency power source 5 on the upper part of chamber 11, heater / lower electrode 9 for placing wafer 8 on the lower part of chamber, low frequency power source 6, and exhaust part 1 on chamber side wall.
0 is provided for each. The N ₂ gas pipe 18 may be used if necessary.

Next, CVD is performed using each embodiment of the present invention.
The case of forming a film will be described.

First, description will be made with reference to the CVD apparatus of the first embodiment shown in FIG. NH ₃ as the first step of film formation
By opening the gas valve 15, the SiH ₄ gas valve 16 and the final valve 14, SiH ₄ gas and NH ₃ gas were introduced into the chamber 11 through the shower head / upper electrode outer peripheral portion 7A to form a SiN film. The film forming temperature was controlled at 400 ° C. and the chamber pressure was controlled at 4 to 5 Torr. Then, by applying powers of about 500 W and 500 W to the high-frequency power supply 5 and the low-frequency power supply 6, respectively, Si having a film thickness of about 100 nm is formed on the wafer 8 at this stage.
An N film was formed.

Next, as a second step, after forming the SiN film, the high frequency power source 5 and the low frequency power source 6 are turned off, and the NH ₃ gas valve 15 and the SiN ₄ gas valve 16 are connected to the chamber 1.
The residual gas in the pipe between 1 is exhausted.

Next, as a third step, by opening the final valve 12, N ₂ O gas is introduced into the chamber 11 via the shower head / upper electrode outer peripheral portion 7A,
By opening the final valve 13, SiF ₄ gas is introduced into the chamber 11 through the shower head / upper electrode central portion 7B. Further, by opening the SiH ₄ gas valve 16 and the final valve 14, SiH ₄ gas was introduced into the chamber 11 to form a SiOF film. The substrate temperature was controlled to 400 ° C. and the chamber pressure was controlled to 4 to 5 Torr. Then, by applying approximately 500 W and 500 W to the high frequency power source 5 and the low frequency power source 6, respectively, a SiOF film having a thickness of approximately 800 nm was formed on the wafer 8 at this stage.

Next, as a fourth step, after forming the SiOF film, the high frequency power source 5 and the low frequency power source 6 are turned off, and the final valves 12 and 13 are closed, whereby N ₂ O gas,
By stopping the SiF ₄ gas and closing the SiH ₄ gas valve 16, the introduction of the SiH ₄ gas is stopped, and the residual gas in the pipe between the final valves 12, 13, the NH ₃ gas valve 15, the SiH ₄ gas valve 16 and the chamber 11 is removed. Exhaust. Then, the process proceeds to the next film forming step.

When this CVD apparatus is used, since the SiF ₄ gas line and the NH ₃ gas line are separated, the SiF ₄ gas and the NH ₃ gas do not merge in the pipe at any step. It was possible to realize the continuous formation of the SiN film and the SiOF film without the product clogged.

Next, description will be given with reference to the CVD apparatus of the second embodiment shown in FIG. First, as the first step of film formation,
By opening the NH ₃ gas valve 15, the SiH ₄ gas valve 16 and the final valve 14, the NH ₃ gas and the SiH ₄ gas were introduced into the chamber 11 through the shower head / upper electrode 7 to form a SiN film. At this time, the final valve 13 interlocking with the NH ₃ gas valve 15 is closed. The film forming temperature was controlled at 400 ° C. and the chamber pressure was controlled at 4 to 5 Torr. The high-frequency power source 5 and the low-frequency power source 6 have about 500 W and 500
By applying the power of W, a SiN film having a film thickness of about 100 nm was formed on the wafer 8 at this stage.

Next, as a second step, after forming the SiN film, the high frequency power source 5 and the low frequency power source 6 are turned off, and the NH ₃ gas valve 15 and the SiH ₄ gas valve 16 are closed to remove the NH ₃ gas and the SiH ₄ gas. Stop the introduction, final valves 12, 13 and NH ₃ gas valve 1
5, The residual gas in the pipe between the SiH ₄ gas valve 16 and the chamber 11 is exhausted.

Next, as a third step, the final valve 14 is closed and the residual gas in the pipe between the final valves 12, 13, 14 and the chamber 11 is exhausted.

Next, as a fourth step, by opening the final valve 12, N ₂ O gas is introduced into the chamber 11 via the shower head / upper electrode outer peripheral portion 7A, and by opening the final valve 13, SiF ₄ gas is supplied.
By opening the SiH ₄ gas valve 16 and the final valve 14, SiH ₄ gas was introduced into the chamber 11 through the shower head / upper electrode 7 to form a SiOF film. At this time, the NH ₃ gas valve 15 linked with the final valve 13 is closed. Film formation temperature is 400
The chamber pressure and the chamber pressure were controlled to 4 to 5 Torr. And about 5 each for the high frequency power source 5 and the low frequency power source 6, respectively.
By applying 00 W and 500 W, a SiOF film having a film thickness of about 800 nm was formed on the wafer 8 at this stage.

Next, as a fifth step, after forming the SiOF film, the high frequency power source 5 and the low frequency power source 6 are turned off, and the final valves 12 and 13 are closed, so that N ₂ O gas,
SiF ₄ gas was added to SiH by closing the valve 16.
The introduction of the ₄ gas is stopped, and the residual gas in the pipe between the final valves 12 and 13, the NH ₃ gas valve 15, and the SiH ₄ gas valve 16 and the chamber 11 is exhausted.

Next, as a sixth step, the final bubble 14 is closed, and the residual gas in the pipe between the final bubbles 12, 13, 14 and the chamber 11 is exhausted.

When this apparatus was used, since SiF ₄ and NH ₃ did not join in the pipes at any step, a continuous film could be realized without the occurrence of clogging. Further, as compared with the first embodiment, as a structure of the apparatus, a shower head / upper electrode 7 for introducing each gas into the chamber 11 is provided.
Is common to all gases, and the conventional CVD shown in FIG.
Since only the piping needs to be replaced when modifying the equipment,
There is a merit that can be realized at low cost.

Next, description will be given with reference to the CVD apparatus of FIG. 3 of the third embodiment. First, as the first step of film formation,
By opening the NH ₃ gas valve 15, the SiH ₄ gas valve 16 and the final valve 14, SiH ₄ gas and NH ₃ were introduced into the chamber 11A via the NH ₃ and SiH ₄ gas nozzles 3A to form a SiN film.
Deposition temperature is 400 ° C, chamber pressure is 4-5 mTorr
Controlled to r. Then, the high-frequency power supplies 5A and 5B have about 1000 W to 4000 W and about 3000 to 40 W, respectively.
By applying a power of 00 W, a SiN film having a film thickness of about 100 nm was formed on the wafer 8 at this stage.

Next, as a second step, a SiN film is formed.
After turning off the high frequency power supplies 5A and 5B,₃ Gas valve
15 and SiF_Four By closing the gas valve 16
NH ₃ Gas and SiH_Four Stop the introduction of gas,
Null valves 12, 13 and NH₃ Gas valve 15, S
iH_Four In the pipe between the gas valve 16 and the chamber 11
Exhaust residual gas.

Next, as a third step, the final bubbles 12, 13 and the SiH ₄ gas valve 16 are opened to supply N ₂ O gas to the N ₂ O gas nozzle 1A, respectively.
The SiF ₄ gas is fed to the SiF ₄ gas nozzle 2A and SiH ₄
The gas was introduced into the chamber 11A through the NH ₃ and SiH ₄ gas nozzles 3A to form a SiOF film. The film forming temperature was controlled at 400 ° C. and the chamber pressure was controlled at 4 to 5 mTorr. And about 1000W-4000W, about 3000-4000W to the high frequency power supplies 5A and 5B, respectively.
By applying the power of, a SiOF film having a film thickness of about 800 nm was formed on the wafer 8 at this stage.

Next, as a fourth step, after forming the SiOF film, the high frequency power supplies 5A and 5B are turned off, and the final bubbles 12 and 13 and the SiH ₄ gas valve 16 are closed, so that the N ₂ O gas, the SiF ₄ gas and the SiH ₄ gas are formed. The introduction of gas is stopped and the final valves 12, 13 and S
The residual gas in the pipe between the iH ₄ gas valve 16 and the chamber 11A is exhausted.

When this CVD apparatus was used, SiH ₄ and NH ₃ did not merge in any of the steps at any step, so that a continuous film could be realized without clogging. First,
Compared with the second embodiment, there is an advantage that a high quality film can be formed because high density plasma is used.

Next, the CVD apparatus of FIG. 4 of the fourth embodiment
Will be described with reference to. First, as the first step of film formation,
NH₃ Gas valve 15, SiH_Four Gas valve 16, NH
₃ ・ SiH_Four Valve 14A and final valve 20
Open the SiH _Four Gas and NH₃ Gas
Introduced into chamber 11 via shower head and upper electrode
Then, a SiN film was formed. At this time, NH₃ Gas valve
SiF working with 15_Four Close the gas valve 13A
There is. Film formation temperature is 400 ° C, chamber pressure is 4-5T
Controlled to orr. And high frequency power supply 5, low frequency
Power of about 500W and 500W respectively to the wave power source 6
By doing so, the film thickness on the wafer 8 is about 100 at this stage.
nm SiOF film was formed.

Next, as a second step, after forming the SiN film, the high frequency power source 5 and the low frequency power source 6 are turned off, and the NH ₃ gas valve 15 and the SiF ₄ gas valve 16 are closed to remove the SiH ₄ gas and the NH ₃ gas. Installation stopped, N
₂ gas valve 19, SiH ₄ gas valve 13A, NH ₃
The residual gas in the pipe between the chamber 11 is exhausted from the gas valve 15, the SiH ₄ gas valve 16 and the exhaust valve 22.

Next, as a third step, NH ₃ .SiH
By closing the ₄ valve 14A and opening the N ₂ gas valve 19, the SiF ₄ gas valve 13A, the NH ₃ · SiH ₄ valve 14A, the exhaust valve 22 and the final valve 2
N ₂ is sealed in the pipe between 0.

Next, as the fourth step, the exhaust valve 22
By opening, the inside of the pipe between the N ₂ gas valve 19, the SiF ₄ gas valve 13A, the NH ₃ · SiH ₄ valve 14A, and the final valve 20 is vacuum-replaced.

Next, as a fifth step, N₂ O Gas Bar
N by opening knob 12₂ O gas shower head
It is also introduced into the chamber 11 via the upper electrode 7 and the exhaust valve.
Close the bush 22, SiF_Four Gas valve 13A, NH₃ ・ S
iH_Four Valve 14A, SiH _Four Gas valve 16 and
By opening the inner valve 20, SiF_Four Gas
And SiH_Four Gas is passed through the shower head and upper electrode 7
It is introduced into the chamber 11 and a SiOF film is formed. this
When SiF_Four NH linked with gas valve 13A₃ 
The gas valve 15 is closed. Substrate temperature is 400 ℃,
The chamber pressure was controlled at 4 to 5 and Torr.
The high-frequency power source 5 and the low-frequency power source 6 each have about 500
Wafer 8 at this stage by applying W and 500W
An SiOF film having a film thickness of about 800 nm was formed on top.

Next, as a sixth step, a SiOF film is formed.
After the film, turn off the high frequency power source 5 and the low frequency power source 6,₂ O moth
N by closing the valve 12₂ Stop O gas,
SiF_Four Gas valve 13A and SiH_Four Gas valve 1
SiF by tightening 6 _Four Gas and SiH_Four gas
Stop, N₂ Gas valve 19, SiF_Four Gas valve 1
3A, NH₃ Gas valve 15, SiH_Four Gas valve 16
And remaining in the pipe between the exhaust valve 22 and the chamber 11.
Exhaust the residual gas.

Next, as a seventh step, NH ₃ .SiH
By closing the ₄ valve 14A and opening the N ₂ gas valve 19, the SiF ₄ gas valve 13A, the NH ₃ · SiH ₄ valve 14A, the exhaust valve 22 and the final valve 2
N ₂ is sealed in the pipe between 0.

Next, as the eighth step, as in the fourth step, the exhaust valve 22 is opened to open the N ₂ gas valve 19, the SiF ₄ gas valve 13A, and the NH ₃ · SiH ₄ gas.
The inside of the pipe between the valve 14A and the final valve 20 is vacuum replaced.

When this CVD apparatus is used, the inside of the pipe is evacuated after forming the SiN film or the SiOF film, and then N ₂
Since the sealing is performed and the vacuum replacement is performed, there is an advantage that the residual gas in the pipe can be exhausted more efficiently than in the second embodiment. As a result, SiF ₄ and NH ₃ do not mix in the pipe at any step,
A continuous film could be realized without the occurrence of clogging.

In the film forming method using the fourth embodiment, the vacuum replacement and the N ₂ pressurization between the final valve 20 and the exhaust valve 22 are repeated, but the N _{2 is} enclosed by performing the vacuum replacement sufficiently. It is possible to omit it.

In the above embodiment, the present invention is applied to the parallel plate type plasma CVD apparatus and the high density plasma CV.
The case of application to the D apparatus has been described, but it goes without saying that the present invention can also be applied to a remote plasma CVD apparatus having a structure in which plasma is generated at another location and the plasma is introduced into the chamber.

[0056]

As described above, according to the present invention, the same char is used.
A continuous deposition process for the SiN film and the SiOF film.
In the Zuma CVD equipment, NH₃ Gas and SiF_Four Gas
Separate gas line or NH₃ Gas piping and SiF_Four gas
Separate valves are installed that are linked to each pipe
Introduced into the chamber with the existing gas line, SiF
_Four Gas and NH₃ The gas may react in the pipe at room temperature.
No, therefore NH in the pipe₃ And SiF_Four Reactant
[(NH_Four )₂ SiF₆ ] Is not generated,
It has an effect of preventing the formation of a reaction product. Also,
SiN film and SiOF film can be continuously formed in the same chamber.
Can reduce costs and improve throughput.
The effect is that it can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view of a CVD apparatus showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a CVD apparatus showing a second embodiment of the present invention.

FIG. 3 is a sectional view of a CVD apparatus showing a third embodiment of the present invention.

FIG. 4 is a sectional view of a CVD apparatus showing a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a conventional CVD apparatus.

FIG. 6 is a sectional view of another conventional CVD apparatus.

FIG. 7 is a sectional view of another conventional CVD apparatus.

[Explanation of symbols]

1, 1A N ₂ O gas pipe 2, 2A SiF ₄ gas pipe 3 NH ₃ gas pipe 3A NH ₃ and SiH ₄ gas nozzle 4 SiH ₄ gas pipe 5, 5A, 5B High frequency power source 6 Low frequency power source 7 Shower head / upper electrode 7A Shower head / upper electrode outer peripheral part 7B Shower head / upper electrode central part 8 Wafer 9 Heater / lower electrode 10, 10A Exhaust part 11, 11A Chamber 12 Final valve 13 Final valve 13A SiF ₄ gas valve 14, 14B Final valve 14A NH ₃ SiH ₄ valve 15 NH ₃ gas valve 16 SiH ₄ gas valve 18 N ₂ gas pipe 19 N ₂ gas valve 20 final valve 21 gas exhaust part 22 exhaust valve 23 final valve

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Tsuchiya 5-7-1, Shiba, Minato-ku, Tokyo Within NEC Corporation (72) Inventor Shigeo Ishikawa 5-7-1, Shiba, Minato-ku, Tokyo NEC (56) References JP 63-302523 (JP, A) JP 10-144683 (JP, A) JP 8-213378 (JP, A) JP 6-281052 (JP, A) JP 64-47872 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/31 C23C 16/34 C23C 16/40 C23C 16/455

Claims (6)

(57) [Claims] 1. In a plasma CVD apparatus for forming a silicon nitride film and a fluorine-containing silicon oxide film in the same chamber, NH is used as a part of a raw material gas for the silicon nitride film.
₃ and NH ₃ gas pipe for introducing a gas, a plasma, characterized in that connected to the fluorine-containing silicon oxide film as part SiF ₄ SiF ₄ gas showerhead-upper electrode separately pipe for introducing a gas of the material gas CVD equipment. 2. The shower head / upper electrode is made of Si.
The plasma CVD according to claim 1, comprising a shower head / upper electrode center portion connected to a SiF ₄ gas pipe for introducing F ₄ gas and a shower head / upper electrode peripheral portion connected to another gas pipe. apparatus. 3. In a plasma CVD apparatus for forming a silicon nitride film and a fluorine-containing silicon oxide film in the same chamber, NH is used as a part of a raw material gas for the silicon nitride film.
₃ and NH ₃ gas pipe for introducing a gas, has its own separate valve in front of SiF ₄ gas pipe merges to introduce SiF ₄ gas as part of the raw material gas of the fluorine-containing silicon oxide film, the SiF ₄ gas pipe Installed valve and N
A plasma CVD apparatus characterized in that a valve installed in an H ₃ gas pipe is interlocked with each other, and when one is open, the other is closed. 4. A mechanism having a valve installed in the SiF ₄ gas pipe, a valve installed in the NH ₃ gas pipe, and a valve between the chambers so that the gas pipe between the valves can be independently vacuum-replaced. The plasma CVD apparatus according to claim 3, which comprises. 5. A valve installed in the SiF ₄ gas pipe, a valve installed in the NH ₃ gas pipe, and a valve between the chambers, and the gas pipe between these valves is evacuated and N ₂ is singly replaced. The plasma CVD apparatus according to claim 3, further comprising a mechanism capable of repeating pressurization. 6. The plasma CVD apparatus according to claim 1 or 3, wherein the plasma CVD apparatus is a parallel plate type plasma CVD apparatus, a high density plasma CVD apparatus, or a remote plasma CVD apparatus.